This invention relates to a kerfless slitter and, in particular, to a kerfless slitter for producing straight edge pieces without the loss of material.
Although the apparatus is capable of slitting a wide variety of materials it is ideally suited for use in the lumber and woodworking industries in cutting a cant or board to a desired size. Traditionally, saws have been employed to carry out this task wherein the blade enters the work at a relatively high speed and cuts a kerf of some finite width in the workpiece. During the cutting operation, a good deal of material is removed by the blade as sawdust. It is well known that sawdust has little or no reclaimable value because the destruction of the wood fibers produced by the blade action renders the material unusable in the manufacture of paper or fiberboard products. As a consequence, most of the sawdust generated in the industry represents an unwanted waste product that is difficult to recycle and which is not readily disposable.
Attempts have been made to slit certain materials such as wood in order to reduce the amount of sawdust generated by conventional saws. As evidenced by U.S. Pat. Nos. 1,691,102; 1,788,456; 3,044,510 and 3,494,396 most of the efforts have been directed toward devices utilizing circular or linear knives having continuous uninterrupted blades. Typically the edge of the blade is forced into a moving workpiece while at the same time the blade is rotated or reciprocated at relatively high speeds to provide a cutting action. High speed movement of the blade oftentimes generates a good deal of heat which shortens the blade life and causes the work to become scored or burned. Similarly, driving the blade at these speeds also required the use of now critical energy.
As noted in the above cited patents, many slitters, in order to produce a relatively linear cut, require that the work be rigidly supported as it moves through the blade to prevent the work from walking while being acted upon by the high speed tool. Any interruption or inconsistency found in the work material, such as splits or grain deviations contained in wood, will tend to align themselves with the blade as it is being forced through the work causing the work to deviate from its intended path of travel thereby reducing the quality of the product. Even with the work well supported in the work zone, it is still possible to deform the thin blade as it is forced through the work which, again, reduces the quality of the final product.